The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
This invention relates to a system and method to reduce sound underwater. More particularly, this invention reduces the transmission of acoustic output from underwater explosions to mitigate the effects on marine mammals and endangered, threatened, or protected species within the vicinity of the explosions.
Exploding live ordnance during training exercises and testing explosives generally tend to attract unfavorable attention. The intense shock waves that have been created by unrestricted underwater detonations have taken their toll of marine life, and in some cases, steps are being taken to restrict this activity. Particularly when explosives are detonated underwater near the shore and in some other regions in the ocean, environmentalists are alarmed by the effects of explosions on all aspects of the marine habitat.
However, an important part of an effective research and development program for national defense purposes is thorough testing of new explosive compounds and ordnance items in their intended underwater applications. Extensive underwater testing often must take place to see if innovative designs can survive in the harsh marine environment and function sell enough to assure successful completion of a mission.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for a system and method to reduce the acoustic output created by detonations of explosives underwater from reaching areas of interest to mitigate impact on marine mammals, fish, and the marine ecosystem as a whole.
An object of the invention is to provide a system and method to reduce the transmission of acoustic outputs caused by detonations of explosives underwater.
Another object of the invention is to provide a system and method to mitigate the effect of underwater explosions on marine mammals and endangered, threatened, or protected species within an area adjacent to the explosions.
Another object of the invention is to provide a system and method to form a curtain, or wall of bubbles between underwater explosions and areas of concern.
Another object of the invention is to provide a system and method to form a curtain, or wall of bubbles from gas generating devices that have gas producing means activated by a control unit.
Another object of the invention is to provide a system and method to form a curtain, or wall of bubbles vented from holes in tubing assemblies to extend from the bottom to the surface of a body of water between detonating explosives and areas of concern.
Another object of the invention is to provide a system on the bottom of a body of water to percolate a curtain of bubbles upward through the water to mitigate shock waves from detonating explosives.
Another object of the invention is to provide a system at the surface of a body of water to drop a wall, or curtain of particulate-like matter, such as sand, to mitigate the shock waves travelling from detonating explosives.
Another object of the invention is to provide a system and method to mitigate shock waves from detonating explosives by venting bubbles through a series of holes in elongate tubing assemblies located between the explosives and areas of concern.
Another object of the invention is to provide a system and method to mitigate shock waves from detonating explosives on areas of concern by venting bubbles through a series of holes that may be differently sized in elongate tubing assemblies located between the explosives and areas of concern.
Another object of the invention is to provide a system and method to mitigate shock waves from detonating explosives on areas of concern by using gas generating devices to create volumes of an environmentally friendly gas and force the gas volumes through tubing assemblies and into ambient water as a curtain of bubbles.
These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims.
Accordingly, the sound mitigation system and method of the invention reduce transmission of acoustic outputs from explosions underwater. The system is submerged to bottom terrain of a body of water and has at a series of gas-generating devices providing volumes of gas that are fed to elongate tubing assemblies. The tubing assemblies extend between adjacent gas generating devices and are provided with at least one row of holes to vent bubbles of gas and form a virtually continuous curtain of bubbles rising to the surface of the water between detonating explosives and areas of interest.